Published: June 26, 2013

WASHINGTON — In a pair of major victories for the gay rights movement, the Supreme Court on Wednesday ruled that married same-sex couples were entitled to federal benefits and, by declining to decide a case from California, effectively allowed same-sex marriages there.

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What is your reaction to the Supreme Court's ruling that struck down the Defense of Marriage Act? Review a selection of key statements from justices on both sides of United States v. Windsor and share your perspective.

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People celebrated outside the Supreme Court on Wednesday after it struck down the Defense of Marriage Act. More Photos »

The rulings leave in place laws banning same-sex marriage around the nation, and the court declined to say whether there was a constitutional right to such unions. But in clearing the way for same-sex marriage in California, the nation’s most populous state, the court effectively increased to 13 the number of states that allow it.

The decisions will only intensify the fast-moving debate over same-sex marriage, and the clash in the Supreme Court reflected the one around the nation. In the hushed courtroom Wednesday morning, Justice Anthony M. Kennedy announced the majority opinion striking down the federal law in a stately tone that indicated he was delivering a civil rights landmark. After he finished, he sat stonily, looking straight ahead, while Justice Antonin Scalia unleashed a cutting dissent.

The vote in the case striking down the federal Defense of Marriage Act was 5 to 4, and Justice Kennedy was joined by the four members of the court’s liberal wing. The ruling will immediately extend many benefits to couples married in the states that allow such unions, and it will allow the Obama administration to broaden other benefits through executive actions.

The case concerning California’s ban on same-sex marriage, enacted in a ballot initiative known as Proposition 8, was decided on technical grounds, with the majority saying that it was not properly before the court. Because officials in California had declined to appeal a trial court’s decision against them, and because the proponents of the ban were not entitled to step into the state’s shoes to appeal the decision, the court said, it was powerless to issue a decision. That left in place a trial court victory for two same-sex couples who had sought to marry.

The vote in the California case was also 5 to 4, but with a different and very unusual alignment of justices. Chief Justice John G. Roberts Jr. wrote the majority opinion, and he was joined by Justice Scalia and Justices Ruth Bader Ginsburg, Stephen G. Breyer and Elena Kagan. The four dissenters — Justice Kennedy and Justices Clarence Thomas, Samuel A. Alito Jr. and Sonia Sotomayor — said they would have decided whether Proposition 8 was constitutional. But they did not say how they would have voted.

The case on the federal law was the more important one from a legal perspective, setting the terms for challenges to state bans on same-sex marriage. Justice Kennedy’s reasoning, as Justice Scalia noted at length in dissent, could just as easily have applied to state laws as to the federal one.

“The federal statute is invalid, for no legitimate purpose overcomes the purpose and effect to disparage and injure those whom the state, by its marriage laws, sought to protect in personhood and dignity,” Justice Kennedy wrote. “By seeking to displace this protection and treating those persons as living in marriages less respected than others, the federal statute is in violation of the Fifth Amendment.”

He said the law was motivated by a desire to harm gay and lesbian couples and their families, demeaning the “moral and sexual choices” of such couples and humiliating “tens of thousands of children now being raised by same-sex couples.”

The constitutional basis for striking down the law was not entirely clear, as it had elements of federalism, equal protection and due process. Justice Kennedy said the law’s basic flaw was in its “deprivation of the liberty of the person protected by the Fifth Amendment.”

He added that the ruling applied only to marriages from states that allowed gay and lesbian couples to wed.

Dissenting from the bench, Justice Scalia said that that declaration took “real cheek.”